Low flow-restriction shut-off valve with excess flow closure functionality

ABSTRACT

A shut-off valve for use in a fluid transport or storage system includes a body defining an inlet port, an outlet port, and a fluid flow passageway extending between the inlet port and the outlet port, a seat arranged in the body adjacent the outlet port, a shaft at least partially disposed in the body, and a control assembly disposed in the body and operatively coupled to the shaft. The control assembly is movable between a closed position, in which a portion of the control assembly sealingly engages the seat to seal the outlet port, and an open position, in which the control assembly is spaced away from the outlet port and substantially outside of the fluid flow passageway, such that the control assembly provides minimal flow-restriction to fluid flowing through the fluid flow passageway.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/158,368, entitled “Low Flow-Restriction Shut-OffValve With Excess Flow Closure Functionality” and filed May 7, 2015, andU.S. Provisional Patent Application No. 62/167,887, entitled “LowFlow-Restriction Shut-Off Valve With Excess Flow Closure Functionality”and filed May 28, 2015, and is related to co-pending U.S.Non-Provisional patent application Ser. No. ______, entitled “ActuatorAssembly for a Low Flow-Restriction Shut-Off Valve With Excess FlowClosure Functionality,” (Ref. No.: 06005/573286); the entire disclosureof each of these applications is hereby expressly incorporated byreference herein for all uses and purposes.

FIELD OF THE DISCLOSURE

The present disclosure is directed to process transfer or controlsystems and, more particularly, to a low flow-restriction shut-off valvewith excess flow closure functionality for use in a process transfer orcontrol system.

BACKGROUND

Gas storage and distribution systems, such as systems used to store anddistribute liquefied natural gas or liquefied petroleum gas, typicallystore gas from a producer in one or more tanks and then transport anddeliver gas to a customer tank along a series of pipes and through aseries of valves. In liquefied petroleum (LP) gas applications, the gastank transfer system typically includes one or more excess flow internalvalves that close in response to breakage in the gas storage anddistribution system (e.g., due to damage in the downstream piping).However, these excess flow valves tend to undesirably introduce highflow-restriction into the system, which in turn leads to flow disruptionand cavitation. Meanwhile, in liquefied natural gas (LNG) applications,the gas distribution system typically includes one or more gate or ballvalves that function as primary shutoff valves. However, these gate orball valves do not have the excess flow functionality provided by excessflow valves and do not offer much, if any, additional functionality.

SUMMARY

In accordance with a first exemplary aspect, a shut-off valve for use ina fluid transport or storage system includes a body defining an inletport, an outlet port, and a fluid flow passageway extending between theinlet and the outlet, a seat arranged in the body adjacent the outletport, a shaft at least partially disposed in the body, a driving elementdisposed in the body and coupled to the shaft, and a valve memberdisposed in the body and operatively coupled to the shaft. The valvemember is movable between a closed position, in which the valve membersealingly engages the seat to seal the outlet port, and an openposition, in which the valve member is spaced away from the outlet portand substantially outside of the fluid flow passageway, such that thevalve member provides minimal flow-restriction to fluid flowing throughthe fluid flow passageway.

In accordance with a second exemplary aspect, a shut-off valve for usein a fluid transport or storage system includes a body defining an inletport, an outlet port, and a fluid flow passageway extending between theinlet port and the outlet port, a seat arranged in the body adjacent theoutlet port, a shaft at least partially disposed in the body, and acontrol assembly disposed in the body and operatively coupled to theshaft. The control assembly is movable between a closed position, inwhich a portion of the control assembly sealingly engages the seat toseal the outlet port, and an open position, in which the controlassembly is spaced away from the outlet port and substantially outsideof the fluid flow passageway, such that the control assembly providesminimal flow-restriction to fluid flowing through the fluid flowpassageway.

In accordance with a third exemplary aspect, a shut-off valve for use ina fluid transport or storage system includes a body defining an inletport, an outlet port, and a fluid flow passageway extending between theinlet and the outlet, a seat arranged in the body adjacent the outletport, a shaft at least partially disposed in the body, a driving elementdisposed in the body and coupled to the shaft, and a valve memberdisposed in the body and operatively coupled to the shaft. The valvemember is movable between a closed position, in which the valve membersealingly engages the seat to seal the outlet port, and an openposition, in which the valve member is spaced away from the outlet portand substantially outside of the fluid flow passageway, such that thevalve member provides minimal flow-restriction to fluid flowing throughthe fluid flow passageway. The shut-off valve also includes a break-awaysafety mechanism including a circumferential channel formed in the valvebody between the outlet port and the seat.

In further accordance with any one or more of the foregoing first,second, or third exemplary aspects, a shut-off valve may include any oneor more of the following further preferred forms.

In one preferred form, the valve member automatically moves to theclosed position responsive to fluid flow through the fluid flowpassageway greater than a predetermined limit.

In another preferred form, the valve member includes a bleed portconfigured to facilitate bleeding through the fluid flow passageway whenthe fluid flow through the fluid flow passageway is greater than thepredetermined limit.

In another preferred form, the driving element is disposed between anexterior wall of the valve body and the valve member.

In another preferred form, a first biasing element is disposed betweenthe driving element and the valve body. The first biasing element isconfigured to bias the driving element to a closed position.

In another preferred form, a second biasing element is arranged to biasthe driving element and the valve member toward one another.

In another preferred form, the shaft protrudes outward of the body andis adapted to be coupled to an external actuator for controlling theshaft.

In another preferred form, the shaft is movable about an axissubstantially perpendicular to the fluid flow passageway.

In another preferred form, the shaft is rotatable about the axis, andthe valve member includes a swinging valve member.

In another preferred form, the shaft is slidable along the axis.

In another preferred form, the shut-off valve includes an adjuster foradjusting the excess flow capacity. The adjuster is configured to engagethe drive member to change a position of the drive member in the closedposition.

In another preferred form, the shaft is rotatable about an axissubstantially perpendicular to the fluid flow passageway.

In another preferred form, the shaft is slidable along an axissubstantially perpendicular to the fluid flow passageway.

In another preferred form, the shut-off valve includes a ramp arrangedin the valve body, the ramp defining a guide path oriented at an anglerelative to the axis. The shaft is coupled to the control assembly via alinkage element guided by the ramp.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention may bebest understood by reference to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals identify like elements in the several FIGS., in which:

FIG. 1 is a perspective view of one example of an excess flow valveconstructed in accordance with the principles of the present invention;

FIG. 2 is a bottom perspective view of the excess flow valve of FIG. 1;

FIG. 3 is a front perspective view of the internal components of theexcess flow valve of FIG. 1;

FIG. 4 is a plan view of the internal components of the excess flowvalve of FIG. 1, with the excess flow valve shown having welded endconnections;

FIG. 5 is a partial, close-up view of a control assembly shown in FIG.4;

FIG. 6 is another partial, close-up view of the control assembly shownin FIG. 4;

FIG. 7 is a plan view of the internal components of the excess flowvalve of FIG. 1 when the excess flow valve is in a closed position;

FIG. 8 is similar to FIG. 7, but shows the internal components of theexcess flow valve when the excess flow valve is in a first bleedposition;

FIG. 9 is similar to FIG. 7, but shows the internal components of theexcess flow valve when the excess flow valve is in an open position;

FIG. 10 is similar to FIG. 7, but shows the internal components of theexcess flow valve when a valve driver of the excess flow valve is beingopened or closed;

FIG. 11 illustrates one example of an adjuster that can be utilized inthe excess flow valve of FIG. 1 to vary the excess flow capacity of theexcess flow valve;

FIGS. 12A and 12B illustrate another example of an excess flow valveconstructed in accordance with the principles of the present invention;

FIG. 13 is a perspective view of another example of an excess flow valveconstructed in accordance with the principles of the present invention;

FIG. 14 is a front perspective view of the internal components of theexcess flow valve of FIG. 13 when the excess flow valve is in an openposition;

FIG. 15 is a partial, close up view of the internal components of theexcess flow valve of FIG. 13 when the excess flow valve is in a closedposition;

FIG. 16 is a perspective view of one example of an actuator assemblythat can be utilized in connection with another example of an excessflow valve constructed in accordance with the teachings of the presentinvention;

FIG. 17 is a front perspective view of the internal components of theexcess flow valve of FIG. 16 when the excess flow valve is in a closedposition;

FIG. 18 is a front perspective view of the internal components of theexcess flow valve of FIG. 16 when the excess flow valve is in an openposition;

FIG. 19 is a front perspective view illustrating the internal componentsof the excess flow valve of FIG. 16 in each of the closed and openpositions;

FIG. 20 illustrates another example of an excess flow valve constructedin accordance with the principles of the present invention;

FIG. 21 illustrates another example of an excess flow valve constructedin accordance with the principles of the present invention;

FIG. 22 illustrates another example of an excess flow valve constructedin accordance with the principles of the present invention; and

FIG. 23 illustrates another example of an excess flow valve constructedin accordance with the principles of the present invention.

DETAILED DESCRIPTION

FIGS. 1-6 depict a low-restriction excess flow valve 100 constructed inaccordance with the principles of the present invention. The excess flowvalve 100 is generally configured for use in gas or liquid applications(e.g., liquefied petroleum applications, liquefied natural gasapplications, liquefied nitrogen applications), but it will beunderstood that the valve 100 can alternatively or additionally be usedin other process control applications. In use, the excess flow valve 100provides excess flow closure capacity protection while simultaneouslyproviding minimal flow-restriction, thereby minimizing, if noteliminating, flow disruption and cavitation, which often occurs in knownexcess flow valves.

As illustrated in FIGS. 1-3, the excess flow valve 100 includes a valvebody 104, a bonnet 108 coupled (e.g., removably coupled) to the valvebody 104, and a shaft 112 operatively coupled to the valve body 104 viathe bonnet 108.

The body 104 has an inlet connection 116 that defines an inlet port 118,an outlet connection 120 that defines an outlet port 122, and a fluidflow passageway 124 extending between the inlet port 118 and the outletport 122. While not illustrated herein, when the flow valve 100 is usedin gas applications, the inlet connection 116 is connected to a tank(not shown), e.g., a cryogenic tank, and the outlet connection 120 isconnected to piping downstream of the excess flow valve 100. Of course,when the valve 100 is used in other process transfer or controlapplications, the inlet and/or outlet connections 116, 120 can beconnected to components in those process transfer or control systems, asappropriate. The inlet and/or outlet connections 116, 120 can bethreaded, flanged, or welded. When connected, the excess flow valve 100facilitates the transfer of fluid (e.g., gas, liquid) from the tankarranged upstream of the valve 100 to piping arranged downstream of thevalve 100 via the fluid flow passageway 124.

The bonnet 108 is, at least in this example, removably coupled to thevalve body 104, such that the bonnet 108 can be removed and the internalcomponents of the valve 100 arranged therein can be repaired or serviced(and in some cases replaced) while the flow valve 100 remains in-line.The bonnet 108 provides support for the shaft 112, which is partiallydisposed in the valve body 104 along an axis that is substantiallyperpendicular to the fluid flow passageway 124 and protrudes outside ofthe body 104 and the bonnet 108. So positioned, a protruding end 128 ofthe shaft 112 can be coupled to an external actuator (not shown), suchas a pneumatic actuator, a manual actuator, a mechanical actuator, or anelectric actuator. When actuated, the shaft 112 rotates within the valvebody 104 to control fluid flow through the fluid flow passageway 124, aswill be described below.

With continued reference to FIGS. 1-3, the excess flow valve 100 alsoincludes a break-away safety mechanism 132. The break-away safetymechanism 132 in this example takes the form of an area of the valvebody 104 that is locally weaker in tension than the rest of the valvebody 104. Specifically, the break-away mechanism 132 takes the form of achannel 136 that extends circumferentially around the valve body 104between the bonnet 108 and the outlet connection 120. The channel 136focuses tensile stresses so that in the event of an accident thatdamages the downstream piping, the valve body 104 fails in the region ofthe channel 136 before failing at any other location, thereby protectingthe integrity of the internal components of the valve body 104 andsealing any fluid within the valve body 104. Optionally, externalstiffening gussets can be added to the valve body 104 to add strengthand robustness upstream of the break-away point (the location of thebreak-away mechanism 132).

As illustrated in FIGS. 3-6, the excess flow valve 100 also includes aseat 150 and a control assembly 154 that is operatively coupled to theshaft 112 so as to be movable relative to the seat 150 to control thefluid flow through the fluid flow passageway 124. As best illustrated inFIG. 3, the seat 150 is arranged in the valve body 104 adjacent theoutlet port 122. The seat 150 can be integrally formed with the valvebody 104 or can be removably coupled thereto (and thus can be removedand replaced when necessary). The seat 150 can be made of metal, plastic(e.g., an elastomeric material), or combinations thereof. The controlassembly 154 illustrated in FIGS. 3-6 includes a driving element 158, avalve member 162, a first biasing element 166 arranged between thedriving element 158 and the valve body 104, and a second biasing element170 arranged between the driving element 158 and the valve member 162.

As best illustrated in FIGS. 4-6, the driving element 158 in thisexample has a base 174, an arm 178, and a cap 182. The arm 178 extendsoutwardly from the base 174 and is secured to, and surrounds, a portionof the shaft 112, such that the driving element 158 is operativelycoupled to the shaft 112. The cap 182, meanwhile, is coupled to andextends outwardly from a central portion of the base 174. The cap 182can be secured to the base 174 (e.g., via fasteners) or can beintegrally formed with the base 174 of the driving element 158. In anyevent, the cap 182 is configured to engage an interior wall 184 of thevalve body 104 when the driving element 158 is in a fully-open position,thereby serving as a stop for, and preventing any further movement of,the driving element 158.

Referring still to FIGS. 4-6, the valve member 162 in this example takesthe form of a flapper 186 having a base 190 and a pair of parallel arms194. The base 190 in this example has a substantially rectangular shape,though a rounded or other shape is possible. A seating channel 198 isdefined or formed in the base 190 for receiving and sealingly engagingthe seat 150 to shut-off flow through the valve 100 (i.e., to close thevalve 100). The seating surface 198 can be metal, plastic (e.g., made ofan elastomeric material), or combinations thereof. The valve member 162also includes a bleed hole 200 defined or formed in a portion of thebase 190. The bleed hole 200 is configured to facilitate limitedbleeding to facilitate pressure equalization across the valve 100, aswill be described below. The bleed hole 200 in this example is centrallylocated on the base 190 and is surrounded by the seating surface 198,though in other examples the bleed hole 200 can be arranged elsewhere.The arms 194 extend outwardly from the base 190 and are secured to, andsurround, different portions of the shaft 112, such that the valvemember 162 is operatively coupled to the shaft 112. As best illustratedin FIG. 6, in one example the arm 178 of the driving element 158 issecured to the shaft 112 at a position between (i.e., radially inwardof) the arms 194 of the valve member 162.

As best illustrated in FIG. 4, the first biasing element 166 in thisexample, while difficult to see, takes the form of a torsion springhaving one end affixed to an interior portion of the valve body 104 andanother end affixed to a portion of the driving element 158. As such,the first biasing element 166 is configured to bias the valve member 162away from the interior wall 184 of the valve body 104 and toward theseat 150, i.e., to a closed position.

Referring again to FIGS. 4-6, the second biasing element 170 in thisexample takes the form of a torsion spring having one end 204 coupled toa portion of the driving element 158 and another end 208, opposite theend 204, secured around the arms 194 of the valve member 162. Soarranged, the second biasing element 170 is configured to bias thedriving element 158 and the valve member 162 toward one another.

With the valve 100 constructed as described, the valve 100 is configuredto provide an excess flow closure function and, at the same time,minimal flow-restriction. Moreover, the excess flow valve 100 isconfigured to protect the integrity of the valve sealing area andcontain any fluid within the valve 100 in the event of an accident thatdamages piping downstream of the valve 100. FIGS. 7-10 will be used todescribe how the excess flow valve 100 can, in operation, achieve thesefunctions.

FIG. 7 illustrates the valve 100 in its initial, closed position, whichoccurs when the shaft 112 is not actuated by the external actuator(i.e., no external actuation is applied to the shaft 112). Without suchactuation, the control assembly 154 is oriented in a closed position inwhich the driving element 158 and the valve member 162 are substantiallyperpendicular to the fluid flow passageway 124, the valve member 162sealingly engages the seat 150, and the driving element 158 is in directcontact with the valve member 162. The driving element 158 not onlysupports the valve member 162, but also covers the bleed hole 200 of thevalve member 162, thereby preventing any fluid flow between the inletport 118 and the outlet port 122. The control assembly 154 is sooriented because the first biasing element 166 biases the drivingelement 158 toward the seat 150, while the second biasing element 170biases the driving element 158 and the valve member 162 toward oneanother. With no external actuation forces present, the biasing forcesapplied by the first and second biasing elements 166, 170 maintain thecontrol assembly 154 in this closed position. Moreover, any fluid flowupstream of the closed control assembly 154 will apply a net force (inthe leftward direction in FIG. 7) on an underside 157 of the drivingelement 158, helping to maintain the driving element 158 and the valvemember 162 in the closed position.

When, however, an external actuation force that exceeds the biasingforce exerted by the first biasing element 166 is applied by theexternal actuator to the shaft 112, the shaft 112 rotates in such a waythat causes the valve 100, specifically the control assembly 154, tomove to the limited bleed position illustrated in FIG. 8. Morespecifically, the external actuation force rotates the shaft 112 in sucha way that the driving element 158 is rotated about the shaft axis in aclockwise direction, away from the seat 150 and toward the interior wall184 of the valve body 104, as illustrated in FIG. 8. The externalactuation force will, at least in this example, rotate the drivingelement 158 in the clockwise direction until the cap 182 of the drivingelement 158 contacts the interior wall 184, which prevents any furthermovement of the driving element 158. At least initially, until thepressure at the outlet port 122 is substantially equal to the pressureat the inlet port 118, the driving element 158 will be moved away, andthus separated, from the valve member 162. This occurs because thepressure associated with fluid flow upstream of the seat 150 initiallyexceeds the pressure associated with fluid flow downstream of the seat150; therefore, the fluid flow will apply a net force (leftward) on thevalve member 162, keeping the valve member 162 in sealing engagementwith the seat 150. As the driving element 158 has been moved away fromthe valve member 162, thereby uncovering the bleed hole 200, fluid willbegin flowing (or bleeding) to the outlet port 122 through the bleedhole 200 formed in the valve member 162. This bleeding will continueuntil pressure equalization, whereby the pressure at the outlet port 122is substantially equal to the inlet port 118, has been achieved.

When pressure equalization has been achieved, the fluid flow in thevalve 100 will no longer apply any significant forces on the valvemember 162, thereby enabling the valve 100, specifically the controlassembly 154, to move to the fully open position illustrated in FIG. 9.More specifically, pressure equalization enables the valve member 162 toswing or rotate in a clockwise direction toward and into contact withthe driving element 158. The driving element 158 and the valve member162 are subsequently arranged at an angle relative to the fluid flowpassageway 124. The angle may, for example, be approximately 5 degrees,approximately 10 degrees, approximately 15 degrees, or some other valuebetween approximately 0 degrees and approximately 90 degrees. As such,the control assembly 154, particularly the valve member 162, is seatedsubstantially outside of the fluid flow passageway 124, with only an endportion of the control assembly 154 being disposed within the fluid flowpassageway 124. As a result, the control assembly 154, particularly thevalve member 162, provides very little restriction against any fluidflowing in the fluid flow passageway 124. Indeed, this allows the valve100 to have a flow coefficient C_(v) greater than the flow coefficientC_(v) for known excess flow internal valves. As an example, the valve100 may have a flow coefficient C_(v) of approximately 250-350, whereasknown excess flow internal valves typically have a flow coefficientC_(v) of approximately 100. The size and/or shape of the fluid flowpassageway 124 can, if desired, be altered to increase or decrease theflow coefficient C_(v). In any event, the valve 100, by providingminimal fluid flow-restriction, substantially reduces, if noteliminates, the risk for cavitation, which can occur as a result of flowdisruption.

When the control assembly 154 is in the fully open position illustratedin FIG. 9, fluid can flow freely in the fluid flow passageway 124 fromthe inlet port 118 to the outlet port 122. However, in the event thatfluid flow entering the valve 100 through the inlet port 118 reaches anexcess flow condition, the valve 100, specifically the control assembly154, moves to the limited bleed position illustrated in FIG. 8. As isknown in the art, the excess flow condition occurs when the fluid flowreaches or exceeds a predetermined limit, typically caused by pressureloss in the process transfer or control system (e.g., because adownstream pipe has broken, etc.). This predetermined limit may, forexample, correspond to a percentage (e.g., 200%) of the capacity thevalve 100 is designed to handle. In any event, when this excess flowcondition has been reached, the drag force from the fluid entering thevalve 100 through the inlet port 118 will exceed the biasing forceapplied by the second biasing element 170, and, as such, the drag forcewill drive the valve member 162 in a counter-clockwise direction. Thedrag force drives the valve member 162 away from the driving element158, which remains in the fully open position, and toward and intosealing engagement with the valve seat 150. Because the driving element158 remains in the fully open position, the bleed hole 200 in the valvemember 162 is exposed, such that a limited amount of fluid can flow(i.e., bleed) therethrough.

It will be appreciated that because the control assembly 154 issubstantially seated outside of the fluid flow passageway 124 in thefully open position, the pressure drop across the valve member 162 issignificantly lower than the pressure drop seen in known excess flowinternal valves. In other words, the valve 100 has the ability toprovide a higher excess flow capacity than known excess flow internalvalves.

In the event that the process transfer or control system breakage isfixed, thereby alleviating the excess flow condition, the limitedbleeding through the bleed hole 200 persists until pressure equalizationhas been restored. In other words, the control assembly 154 remains inthe bleed position illustrated in FIG. 8, and fluid flows through thebleed hole 200, until the pressure at the outlet port 122 issubstantially equal to the pressure at the inlet port 118. When pressureequalization has been restored, the second biasing element 170 pulls thevalve member 162 back to the position illustrated in FIG. 9, therebyreturning the valve 100, specifically the control assembly 154, to thefully open position.

In the event that the process transfer or control system cannot be fixedor fixing the process transfer or control system is not desirable, thevalve 100 can be easily and safely fully shutoff by de-energizing theexternal actuation (i.e., removing the actuation force applied to theshaft 112). Without any external actuation, the driving element 158 alsoreturns to the closed position illustrated in FIG. 7. More specifically,the driving element 158 moves toward and into contact with the valvemember 162, which is already in sealing engagement with the seat 150.This movement of the driving element 158 covers the bleed hole 200,eliminating the limited bleed through the valve 100 and fully closingthe valve 100.

Optionally, the excess flow valve 100 can, as is illustrated in FIG. 11,include an adjuster 300, e.g., a set screw, that facilitates adjustmentof the excess flow capacity for the valve 100. The adjuster 300 in thisexample is externally exposed and actuatable by an operator of the valve100. The adjuster 300 is movable in a direction substantially parallelto the fluid flow passageway 124. When an operator of the valve 100moves the adjuster 300 inward, toward the outlet port 122, the adjuster300 drives the driving element 158 in a counter-clockwise direction,which in turn changes the angle of the valve member 162 relative to thefluid flow passageway 124. As a result, more of the valve member 162 isdisposed within the fluid flow passageway 124. This serves to reduce theamount of drag force required to move the valve member 162 to the closedposition in the event of an excess flow condition, thereby decreasingthe excess flow capacity of the valve 100. Conversely, when an operatorof the valve 100 moves the adjuster 300 outward, toward the inlet port118, the driving element 158 moves (i.e., falls) in a clockwisedirection, such that less of the valve member 162 is disposed within thefluid flow passageway 124. This action thus serves to increase theamount of drag force required to move the valve member 162 to the closedposition in the event of an excess flow condition, thereby increasingthe excess flow capacity of the valve 100.

In other examples, the adjuster 300 can be arranged internally withinthe valve 100 and actuated in a different manner (e.g., using anexternal actuator). Moreover, the adjuster 300 can be arrangeddifferently relative to the control assembly 154, such that the adjuster300 may be movable in a different direction (e.g., perpendicular to thefluid flow passageway 124) and/or ultimately move the valve member 162in a different manner. Further yet, while the adjuster 300 can beemployed to facilitate adjustment of the excess flow capacity for thevalve 100, the angle of the valve member 162 can be adjusted, withoutusing the adjuster 300, to achieve a similar effect. Likewise, thebiasing elements 166, 170 can be altered, in terms of structure and/orbiasing force, to vary the excess flow capacity of the valve 100. As anexample, the biasing element 166 and/or the biasing element 170 can takethe form of extension springs, compression springs, constant-forcesprings, leaf springs, or other biasing elements (e.g., latches).

It will also be appreciated that the valve body 104, the bonnet 108, theshaft 112, and/or the break-away shaft mechanism 132 can vary from whatis illustrated in FIGS. 1-10 and yet still perform the intendedfunctionality. More specifically, the shape, size, and/or style of thevalve body 104 can vary. In one example, the shape and/or size of theinlet and/or outlet connections 116, 120 can vary, for example when itis desired to utilize the excess flow valve 100 in a differentenvironment having different sized tanks and/or piping. In someexamples, the shaft 112 can be arranged in a different manner, e.g.,oriented along a different axis or located in a different positionrelative to the flow path (e.g., further from the outlet port 122). Asan example, as illustrated in FIGS. 12A and 12B, the shaft 112 can besupported in a different portion of the valve body 104 and orientedalong a different axis relative to the valve body 104. In anotherexample, the shaft 112 can be oriented such that clockwise rotation,rather than counter-clockwise rotation, of the shaft 112 moves thecontrol assembly 154 from the open position to the bleed positions andthe closed position. The shaft 112 can also be entirely contained withinthe valve body 104, such that the shaft 112 does not protrude outside ofthe body 104 (and the valve 100 is an internal valve). In such a case,it may be desirable to introduce a shaft follower immediately adjacentthe outlet port 122. If desired, the break-away safety mechanism 132 cantake on other forms as well. As an example, the break-away safetymechanism 132 may be formed as a gradually thinning portion of the valvebody 104, from a different, weaker material, or using mounting studswith notches or grooves to provide a primary failure location. Thebreak-away shaft mechanism 132 may also be re-positioned as well. As anexample, when the valve 100 is designed as an internal valve andincludes a shaft follower adjacent the outlet port 122, the break-awayshaft mechanism 132 may be located between the seat 150 and the shaftfollower.

Alternatively or additionally, the construction and/or actuation of thecontrol assembly 154 can vary from what is illustrated in FIGS. 1-10 andyet still perform the intended functionality. In other examples, theshape and/or size of the driving element 158 and/or the valve member 162can be varied to, for example, alter the excess flow capacity of thevalve 100, to alter the necessary actuation force and/or biasingforce(s), or for some other reason. In another example, the valve member162 need not include the bleed hole 200, in which case the valve 100would no longer have any sort of bleeding capabilities when respondingto an issue in the process transfer or control system. In otherexamples, the control assembly 154 can also be actuated in a differentmanner. While the control assembly 154 described in connection withFIGS. 1-10 is externally actuated in a rotational manner, the controlassembly 154 can instead be externally or internally actuated in alinear (e.g., sliding) manner, as is, for example, illustrated in FIGS.13-17.

FIGS. 13-15 depict another example of a low-restriction excess flowvalve 400 constructed in accordance with the principles of the presentinvention. Like the excess flow valve 100, the excess flow valve 400 isgenerally configured for use in gas or liquid applications (e.g.,liquefied petroleum applications, liquefied natural gas applications,liquefied nitrogen applications), but it will be understood that thevalve 400 can alternatively or additionally be used in other processcontrol applications. In use, the excess flow valve 400 provides excessflow closure capacity protection while simultaneously providing minimalflow-restriction, thereby minimizing, if not eliminating, flowdisruption and cavitation, which often occurs in known excess flowvalves.

As illustrated in FIGS. 13 and 14, the excess flow valve 400 includes avalve body 404, a bonnet 408 coupled (e.g., removably coupled) to thevalve body 404, and a sliding stem 410 and an internal shaft 412 eachoperatively coupled to the valve body 404 via the bonnet 408.

As illustrated in FIGS. 13 and 14, the body 404 has an inlet connection416 that defines an inlet port 418, an outlet connection 420 thatdefines an outlet port 422, and a fluid flow passageway 424 extendingbetween the inlet port 418 and the outlet port 422. While notillustrated herein, when the flow valve 400 is used in gas applications,the inlet connection 416 is connected to a tank (not shown), e.g., acryogenic tank, and the outlet connection 420 is connected to pipingdownstream of the excess flow valve 400. Of course, when the valve 400is used in other process transfer or control applications, the inletand/or outlet connections 416, 420 can be connected to components inthose process transfer or control systems, as appropriate. The inletand/or outlet connections 416, 420 can be threaded, flanged, or welded.When connected, the excess flow valve 400 facilitates the transfer offluid (e.g., gas, liquid) from the tank arranged upstream of the valve400 to piping arranged downstream of the valve 400 via the fluid flowpassageway 424.

The bonnet 408 is, at least in this example, removably coupled to thevalve body 404, such that the bonnet 408 can be removed and the internalcomponents of the valve 400 arranged therein can be repaired or serviced(and in some cases replaced) while the flow valve 400 remains in-line.The bonnet 408 in this example has a base portion 426 and a cylindricalportion 428 that extends upward from the base 426. The base 426 isremovably coupled to a top portion of the valve body 404. Thecylindrical portion 428 houses the internal shaft 412, which is disposedalong an axis 429 that is substantially perpendicular (e.g.,perpendicular) to the fluid flow passageway 424, and provides supportfor the sliding stem 410, which is also disposed along the axis 429(i.e., the stem 410 and the shaft 412 are co-axial). The sliding stem410 protrudes outside of the bonnet 408, and, more specifically, thecylindrical portion 428 of the bonnet. So positioned, a protruding end430 of the stem 410 (or some other component coupled thereto) can becoupled to an external actuator (not shown), such as a pneumaticactuator, a manual actuator, a mechanical actuator, or an electricactuator, such that the sliding stem 410 can be controlled. Whenactuated, the sliding stem 410 moves upward or downward, which in turnmoves the internal shaft 412 upward or downward in an identical manner.

With continued reference to FIGS. 13 and 14, the excess flow valve 400also includes a break-away safety mechanism 432. Like the break-awaysafety mechanism 132 described above, the break-away safety mechanism432 in this example takes the form of an area of the valve body 404 thatis locally weaker in tension than the rest of the valve body 404.Specifically, the break-away mechanism 432 takes the form of a channel436 that extends circumferentially around the valve body 404 between thebonnet 408 and the outlet connection 420. The channel 436 focusestensile stresses so that in the event of an accident that damages thedownstream piping, the valve body 404 fails in the region of the channel436 before failing at any other location, thereby protecting theintegrity of the internal components of the valve body 404 and sealingany fluid within the valve body 404. Optionally, external stiffeninggussets can be added to the valve body 404 to add strength androbustness upstream of the break-away point (the location of thebreak-away mechanism 432).

As illustrated in FIGS. 14 and 15, the excess flow valve 400 alsoincludes a seat 450 and a control assembly 454 that is movable relativeto the seat 450 to control the fluid flow through the fluid flowpassageway 424. While the seat 450 is integrally formed within the valvebody 404 adjacent the outlet port 422, the seat 450 can alternatively beremovably coupled thereto (and thus can be removed and replaced whennecessary). The seat 450 can be made of metal, plastic (e.g., anelastomeric material), or combinations thereof. The seat 450 can bearranged at an angle relative to the fluid flow passageway 424 and theaxis 429, as is illustrated in FIG. 14, or can be arranged along an axisthat is substantially parallel (e.g., parallel) to the axis 429 (andthus substantially perpendicular to the fluid flow passageway 424).

The control assembly 454 is generally movable relative to the seat 450between an open position, whereby the valve 400 is open and fluid flowis permitted through the fluid flow passageway 424, and a closedposition, whereby the valve 400 is closed and no fluid flow is permittedthrough the fluid flow passageway 424. The control assembly 454 in thisexample includes the sliding stem 410, the internal shaft 412, a drivingelement 458, a valve member 462, a first biasing element 466 arranged inthe cylindrical portion 428 of the bonnet 408 and operatively coupled tothe sliding stem 410, and a second biasing element that is not shown butis arranged between the driving element 458 and the valve member 462(and functions in an identical manner as the second biasing element 170described above). The internal shaft 412 is coupled (e.g., fastened) tothe sliding stem 410. The driving element 458 is, in turn, operativelyconnected to the internal shaft 412 via first and second links 470, 472.When the sliding stem 410 is externally actuated, thereby moving thesliding stem 410, the internal shaft 412 responds by moving in anidentical manner. This drives the first and second links 470, 472, whichfacilitate the desired movement of the driving element 458 and the valvemember 462, as will be described in greater detail below.

As best illustrated in FIGS. 14 and 15, the driving element 458 in thisexample has a base 474, an arm 478, and a neck 482. The arm 478 extendsoutwardly from the base 474 and is secured to, and surrounds, a rod 484pivotally disposed in a channel 485 formed in the valve body 404, suchthat the driving element 458 is pivotally coupled to and within thevalve body 404. The rod 484 and the channel 485 are generally arrangedso as to minimize rotational motion, and overall motion, relative to thevalve body 404, thereby optimizing the sealing engagement between thevalve member 462 and the seat 450. The neck 482 extends outwardly from acentral portion of the base 474. While the neck 482 is integrally formedwith the base 474, the neck 482 can instead be coupled to the base 474(e.g., via fasteners).

Referring still to FIGS. 14 and 15, the valve member 462 in this exampletakes the form of a flapper 486 having a base 490 and a pair of parallelarms 494 (only one of which is visible in FIG. 14). The base 490 in thisexample has a substantially annular shape, though a rectangular or othershape can be utilized instead. While difficult to see in FIGS. 14 and15, a seating channel 498 is defined or formed along a periphery of thebase 490 for receiving and sealingly engaging the seat 450 to shut-offflow through the valve 400 (i.e., to close the valve 400). The seatingsurface 498 can be metal, plastic (e.g., made of an elastomericmaterial), or combinations thereof. The valve member 462 also includes ableed hole 500 defined or formed in a portion of the base 490. The bleedhole 500 is configured to facilitate limited bleeding to facilitatepressure equalization across the valve 400, as will be described below.The bleed hole 500 in this example is centrally located on the base 490and is surrounded by the seating surface 498, though in other examplesthe bleed hole 500 can be arranged elsewhere. The arms 494 extendoutwardly from the base 490 and are secured to, and surround, differentportions of the rod 484, such that the valve member 462, like thedriving element 458, is pivotally coupled to and within the valve body404. While not explicitly illustrated in FIGS. 14 and 15, the arm 478 ofthe driving element 458 is secured to the rod 484 at a position between(i.e., radially inward of) the arms 494 of the valve member 462.

As best illustrated in FIG. 14, the first biasing element 466 in thisexample takes the form of a coil spring 512 arranged within thecylindrical portion 428 of the bonnet 408. More specifically, the coilspring 512 is arranged between a top portion 513 of the bonnet 408 and aseat 516 arranged adjacent an end 518 of the stem 410 opposite theprotruding end 430. So arranged, the first biasing element 466 isconfigured to bias the driving element 458 away from the base 426 of thebonnet 408 and toward the seat 450, i.e., to a closed position (see FIG.15).

While not explicitly illustrated herein, the second biasing element ofthe valve 400 is identical in structure and function to the secondbiasing element 170 described above. As such, the second biasing elementof the valve 400 takes the form of a torsion spring having a first endcoupled to a portion of the driving element 458 and a second end,opposite the first end, secured around the arms 494 of the valve member462. So arranged, the second biasing element of the valve 400 isconfigured to bias the driving element 458 and the valve member 462toward one another.

With reference specifically to FIG. 15, the first link 470 in thisexample takes the form of an H-shaped element 520 that has one portion521 secured (e.g., via fasteners) to the internal shaft 412 and anotherportion 522 pivotally coupled to the second link 472 at a pivot joint523. When the control assembly 454 is in the open position, and for asignificant portion of the travel stroke of the sliding stem 410, thelink element 520 is movably disposed along the axis 429. When, however,the sliding stem 410 is near the end of its travel stroke, and thecontrol assembly 454 is close to the closed position, the pivot joint523 is guided along, and supported by, a ramp 524 that is formed withinand extends inwardly from the valve body 404. As illustrated in FIG. 14,the ramp 524 defines a guide path that is oriented at an angle Θrelative to the axis 429. The guide path may be oriented at anapproximately 5 degree, approximately 10 degree, approximately 15degree, or some other degree angle relative to these axes. In any event,because the ramp 524 defines a slightly curved guide path, the pivotjoint 523, which is guided by the ramp 524, is forced to travel alongthis curved guide path.

The second link 472 is generally configured to convert the translationalmotion of the internal shaft 412 into rotational movement of the drivingelement 458. The second link 472 in this example takes the form of asubstantially cylindrically shaped element 532 having one end 536pivotally coupled to the first link 470 at the pivot joint 523 andanother end 544 pivotally coupled to the neck portion 482 of the drivingelement 458 at a pivot joint 548. So arranged, the link element 532pivots about the pivot joints 523, 548 as the valve 400 is moved betweenthe open and closed positions.

With the valve 400 constructed as described, the valve 400 is configuredto provide an excess flow closure function and, at the same time,minimal flow-restriction. Moreover, the excess flow valve 400 isconfigured to protect the integrity of the valve sealing area andcontain any fluid within the valve 400 in the event of an accident thatdamages piping downstream of the valve 400. FIGS. 14 and 15 will also beused to describe how the excess flow valve 400 can, in operation,achieve these functions.

FIG. 15 illustrates the valve 400 in its initial, closed position, whichis similar to the closed position of the valve 100 described above (andillustrated in FIG. 7) and which occurs when the sliding stem 410 is notactuated by the external actuator (i.e., no external actuation isapplied to the sliding stem 410). Without such actuation, the controlassembly 454 is oriented in a closed position in which the drivingelement 458 and the valve member 462 are slightly angled relative, butsubstantially perpendicular, to the fluid flow passageway 424, the valvemember 462 sealingly engages the seat 450, and the driving element 458is in direct contact with the valve member 462. The driving element 458not only supports the valve member 462, but also covers the bleed hole500 of the valve member 162, thereby preventing any fluid flow betweenthe inlet port 418 and the outlet port 422. The control assembly 454 isso oriented because the first biasing element 466 biases the drivingelement 458 toward the seat 450, while the second biasing element of thevalve 400 biases the driving element 458 and the valve member 462 towardone another. With no external actuation forces present, the biasingforces applied by the first and second biasing elements maintain thecontrol assembly 454 in this closed position. Moreover, any fluid flowupstream of the closed control assembly 454 will apply a net force onthe underside of the driving element 458, helping to maintain thedriving element 458 and the valve member 462 in the closed position.

As FIG. 15 also illustrates, when the valve 400 is in the closedposition, the link element 520 is oriented at an angle relative to thefluid flow passageway 424 and the axis 429, that angle corresponding tothe angle of the guide path defined by the ramp 524. The link element520 converts the vertical, actuation force applied by the externalactuator (and transmitted via the stem 410 and the shaft 412) into ahorizontal, axial force that is transmitted to the link element 532. Thelink element 532, which is substantially parallel to the fluid flowpassageway 424 and substantially perpendicular to the axis 429, appliesthis horizontal force, i.e., applies the force in a directionsubstantially parallel to the fluid flow passageway 424, to the valvemember 462, keeping the valve member 462 in sealing engagement with theseat 450. Not only does the link element 520 help to convert or leveragethe vertical, actuation force into an axial force that keeps the valvemember 462 closed, but because the curved ramp 524 acts upon the pivotjoint 523 in the manner described above, the control assembly 454,particularly the valve member 462, can be maintained in the closedposition with less force than would otherwise be required. In otherwords, because of the curved ramp 524, the stem 410 and the shaft 412need not apply as much as force as conventionally would be required tokeep the valve member 462 in sealing engagement with the seat 450. Thismay, in return, permit the use of a smaller external actuator than wouldotherwise be needed.

When, however, an external actuation force that exceeds the biasingforce exerted by the first biasing element 466 is applied by theexternal actuator to the sliding stem 410, the stem 410 moves in such away that causes the valve 400 to move to a limited bleed position, whichis not shown but is similar to the limited bleed position of the valve100 described above (and illustrated in FIG. 8). More specifically, thestem 410 is driven upward, away from the valve body 404, which causesthe shaft 412 to move upward as well. The external actuation force willdrive the stem 410 upward until it reaches the end of its travel stroke.At least initially, until the pressure at the outlet port 422 issubstantially equal to the pressure at the inlet port 418, the drivingelement 458 will be moved away, and thus separated, from the valvemember 462. This occurs because the pressure associated with fluid flowupstream of the seat 450 initially exceeds the pressure associated withfluid flow downstream of the seat 450; therefore, the fluid flow willapply a net force (leftward) on the valve member 462, keeping the valvemember 462 in sealing engagement with the seat 450. As the drivingelement 458 has been moved away from the valve member 462, therebyuncovering the bleed hole 500, fluid will begin flowing (or bleeding) tothe outlet port 422 through the bleed hole 500 formed in the valvemember 462. This bleeding will continue until pressure equalization,whereby the pressure at the outlet port 422 is substantially equal tothe inlet port 418, has been achieved.

When pressure equalization has been achieved, the fluid flow in thevalve 400 will no longer apply any significant forces on the valvemember 462, thereby enabling the valve 400, specifically the controlassembly 454, to move to the open position illustrated in FIG. 14. Morespecifically, pressure equalization enables the valve member 462 toswing or rotate in a clockwise direction toward and into contact withthe driving element 458. The driving element 458 and the valve member462 are subsequently arranged at an angle relative to the fluid flowpassageway 424. As illustrated in FIG. 14, the control assembly 454,particularly the valve member 462, is seated substantially outside ofthe fluid flow passageway 424, with only an end portion of the controlassembly 454 being disposed within the fluid flow passageway 424. Assuch, the control assembly 454, particularly the valve member 462,provides very little restriction against any fluid flowing in the fluidflow passageway 424. Indeed, this allows the valve 400 to have a flowcoefficient C_(v) greater than the flow coefficient C_(v) for knownexcess flow internal valves. As an example, the valve 400 may have aflow coefficient C_(v) of approximately 250-350, whereas known excessflow internal valves typically have a flow coefficient C_(v) ofapproximately 100. The size and/or shape of the fluid flow passageway424 can, if desired, be altered to increase or decrease the flowcoefficient C_(v). In any event, the valve 400, by providing minimalfluid flow-restriction, substantially reduces, if not eliminates, therisk for cavitation, which can occur as a result of flow disruption.

When the control assembly 454 is in the fully open position illustratedin FIG. 14, fluid can flow freely in the fluid flow passageway 424 fromthe inlet port 418 to the outlet port 422. However, in the event thatfluid flow entering the valve 400 through the inlet port 418 reaches anexcess flow condition, the valve 400, specifically the control assembly454, moves to the limited bleed position discussed above. As is known inthe art, the excess flow condition occurs when the fluid flow reaches orexceeds a predetermined limit, typically caused by pressure loss in theprocess transfer or control system (e.g., because a downstream pipe hasbroken, etc.). This predetermined limit may, for example, correspond toa percentage (e.g., 200%) of the capacity the valve 100 is designed tohandle. In any event, when this excess flow condition has been reached,the drag force from the fluid entering the valve 400 through the inletport 418 will exceed the biasing force applied by the second biasingelement 470, and, as such, the drag force will drive the valve member462 in a counter-clockwise direction. The drag force drives the valvemember 462 away from the driving element 158, which remains in the fullyopen position, and toward and into sealing engagement with the valveseat 450. Because the driving element 458 remains in the fully openposition, the bleed hole 500 in the valve member 462 is exposed, suchthat a limited amount of fluid can flow (i.e., bleed) therethrough.

It will be appreciated that because the control assembly 454 issubstantially seated outside of the fluid flow passageway 424 in thefully open position, the pressure drop across the valve member 462 issignificantly lower than the pressure drop seen in known excess flowinternal valves. In other words, the valve 400 has the ability toprovide a higher excess flow capacity than known excess flow internalvalves.

In the event that the process transfer or control system breakage isfixed, thereby alleviating the excess flow condition, the limitedbleeding through the bleed hole 500 persists until pressure equalizationhas been restored. In other words, the control assembly 454 remains inthe bleed position, and fluid flows through the bleed hole 500, untilthe pressure at the outlet port 422 is substantially equal to thepressure at the inlet port 418. When pressure equalization has beenrestored, the second biasing element pulls the valve member 462 back tothe position illustrated in FIG. 14, thereby returning the valve 400,specifically the control assembly 454, to the fully open position.

In the event that the process transfer or control system cannot be fixedor fixing the process transfer or control system is not desirable, thevalve 400 can be easily and safely fully shutoff by de-energizing theexternal actuation (i.e., removing the actuation force applied to thestem 410). Without any external actuation, the control assembly 454returns to the closed position illustrated in FIG. 15. Morespecifically, the driving element 458 moves toward and into contact withthe valve member 462, which is already in sealing engagement with theseat 450. This movement of the driving element 458 covers the bleed hole500, eliminating the limited bleed through the valve 400 and fullyclosing the valve 400.

FIGS. 16-19 illustrate an actuator assembly 600 operatively coupled toanother example of a low-restriction excess flow valve 604 constructedin accordance with the principles of the present invention. The excessflow valve 604 is substantially similar to the excess flow valve 400illustrated in FIGS. 13-15, with common reference numerals used to referto common components.

As illustrated in FIG. 16, the actuator assembly 600 includes a mountingassembly 608 for mounting an actuator 612 to the valve 604 in a mannerthat does not increase the vertical footprint of the valve 604. Themounting assembly 608 includes a mounting sleeve 616 and a mountingbracket 620. The mounting sleeve 616 is removably coupled to the stem410 (and, as a result, is also movable relative to the valve body 404).More specifically, the mounting sleeve 616 is disposed over asubstantial portion of the cylindrical portion 428 of the bonnet 408,with an upper end 621 of the mounting sleeve 616 secured to theprotruding end 430 of the stem 410 via a fastener 617; if desired, themounting sleeve 616 can be decoupled from the stem 410 by removing thefastener 617. In any event, when the mounting sleeve 616 is coupled tothe stem 410 in the described manner, the stem 410 and the mountingsleeve 616 move upward or downward together, such that movement of thesleeve 616 raises or lowers the stem 410. The mounting bracket 620,meanwhile, is removably secured (e.g., via fasteners) to the baseportion 426 of the bonnet 408. When secured to the bonnet 408, themounting bracket 620 is fixed relative to the valve body 404, such thatthe mounting sleeve 616 is movable relative to the mounting bracket 620.

As also illustrated in FIG. 16, the mounting assembly 608 also includesa pair of arms 618A, 618B that extend outward in a directionperpendicular to the length of the sleeve 616. The first arm 618A iscoupled to, and extends outward from, the mounting bracket 620, whilethe second arm 618B is coupled to, and extends outward from, a portionof the mounting sleeve 616 proximate to the upper end 621. It will thusbe appreciated that the second arm 618B is movable relative to themounting bracket 620 (and the valve body 404), while the first arm 618Ais not, at least in this example.

The actuator 612 is an adjustable shock absorber that has a cylindricalbody 622 and a pair of tube-like ends 624. While not illustrated in FIG.16, the cylindrical body 622 has an inlet adapted to receive a pressuresource, such that the cylindrical body 622 can be pressurized to openthe valve 600. The cylindrical body 622 includes a first body portion623A and a second body portion 623B that is telescopically engaged inthe first body portion 623A. The first body portion 623A is coupled to(e.g., integrally formed with) one of the tube-like ends 624, and thesecond body portion 623B is coupled to (e.g., integrally formed with)the other of the tube-like ends 624. As illustrated in FIG. 16, each ofthe tube-like ends 624 defines an opening that is sized to receive acorresponding one of the arms 618A, 618B when the actuator 612 ismounted to the valve 604 via the mounting assembly 608. The opening ofthe tube-like end 624 of the first body portion 623A receives the arm618A, and the opening of the tube-like end 624 of the second bodyportion 623B receives the arm 618B. By virtue of this arrangement, thesecond body portion 623B can, responsive to pressurization of thecylindrical body 622 via the inlet, move relative to the first bodyportion 623A to increase or decrease an interior area of the cylindricalbody 622.

While the excess flow valve 604 is described above as beingsubstantially similar to the excess flow valve 400, the flow valve 604differs from the flow valve 400 in two main respects. First, the valve604 includes a different means of facilitating limited bleeding than thevalve 400. Unlike the valve 400, which includes the selectively openablebleed hole 500, the valve 604 includes a bleed mechanism 650 thatincludes a bleed hole 654 and a check or bleed valve 658, as illustratedin FIGS. 17 and 18. The bleed hole 654 is defined or formed in the valvein an interior portion of the base 490 of the valve member 462, whilethe bleed valve 658 is arranged in an interior portion of the base 474of the driving element 458 at a position adjacent (e.g., aligned with)the bleed hole 654. The bleed mechanism 650 facilitates back pressurerelief by bleeding fluid through the bleed valve 658 when higherpressure fluid is trapped downstream of the sealed seat 450. As anexample, the bleed mechanism 650 may facilitate bleeding when liquidtrapped downstream of the seat 450 has turned into a higher pressurevapor. The bleed mechanism 650 is advantageous because it reduces, ifnot eliminates, the need for additional relief valves mounted downstreamof the flow valve 604 (when, e.g., trapped liquid downstream turns tohigher pressure vapor). Secondly, the flow valve 604 includes one ormore gauge ports 662 that allow an end user to monitor pressure dropacross the valve 604, e.g., to determine blockage. The flow valve 604illustrated in FIGS. 17 and 18 includes a pair of gauge ports 662, onedisposed adjacent the inlet 418 and one disposed adjacent the outlet422. In other examples, however, the flow valve 604 may only include onesuch gauge port. Regardless, when not being used to monitor pressure,the gauge ports 662 can be plugged.

Notwithstanding these differences, the valve 604 is operable in asimilar manner as the valve 400. FIGS. 16 and 17 illustrate the valve604 in a closed position, which is substantially similar to the closedposition of the valve 400. Here, however, when it is desired to move thevalve 604 from this closed position to the open position illustrated inFIG. 18, which is substantially similar to the open position of thevalve 400, the actuator 612 can be pressurized (e.g., via the inlet ofthe body 622). Pressurization of the actuator 612 causes the second bodyportion 623B to move upward (at least in FIG. 16) relative to the firstbody portion 623A, thereby expanding the actuator body 622, which raisesthe mounting sleeve 616 (which is coupled to the second body portion623B), and, in turn, raises the stem 410 (which is coupled to the sleeve616). Actuation of the stem 410 in this manner moves the driving element458 and the valve member 462 from the closed position shown in FIG. 17to the open position shown in FIG. 18. Conversely, by de-pressurizingthe actuator 612, the valve 604 can be moved from the open position backto the closed position. De-pressurization of the actuator 612 causes thesecond body portion 623B to move downward (at least in this example)relative to the first body portion 623A, thereby contracting theactuator body 622 back to the position shown in FIG. 16, which lowersthe mounting sleeve 616 (which is coupled to the second body portion623B), and, in turn, lowers the stem 410. Actuation of the stem 410 inthis manner moves the driving element 458 and the valve member 462 fromthe open position shown in FIG. 18 back to the closed position shown inFIG. 17. FIG. 19 illustrates the components of the control assembly 454when the valve 400 is in both the closed and open positions.

It will also be appreciated that the valve 400 and/or the valve 604 canvary and yet still perform the intended functionality. The valve body404, the bonnet 408, the stem 410, the shaft 412, and/or the break-awayshaft mechanism 432 can vary from what is illustrated and yet stillperform the intended functionality. More specifically, the shape, size,and/or style of the valve body 404 can vary. In one example, the shapeand/or size of the inlet and/or outlet connections 416, 420 can vary,for example when it is desired to utilize the excess flow valve 400 in adifferent environment having different sized tanks and/or piping. Insome examples, the shaft 412 can be arranged in a different manner,e.g., oriented along a different axis or located in a different positionrelative to the flow path (e.g., further from the outlet port 422).Alternatively or additionally, the construction and/or actuation of thecontrol assembly 454 can vary from what is illustrated and yet stillperform the intended functionality. In other examples, the shape and/orsize of the driving element 458 and/or the valve member 462 can bevaried to, for example, alter the excess flow capacity of the valve, toalter the necessary actuation force and/or biasing force(s), or for someother reason. In other examples, the driving element 458 and the valvemember 462 can be operatively coupled to the stem 410 and the shaft 412in a different manner. For example, as illustrated in FIG. 20, a 2-barmechanism 670 with a sliding joint 674 can be employed instead of thelink element 472. Of course, the shape of the slot that guides thesliding joint can be varied (e.g., the angle can be adjusted) to varythe travel versus force or travel versus opening.

While not described in detail, FIGS. 21, 22, and 23 each illustratealternative excess flow valves 700, 800, and 900, respectively,constructed in accordance with one or more aspects of the presentinvention. The excess flow valves 700, 800, and 900 operate in a similarmanner as the excess flow valves 100, 400, and 604 described herein.

Finally, it will be appreciated that any of the excess flow valvesdescribed herein can include various combinations of the componentsdescribed herein and/or a number of other components not explicitlyillustrated herein. As an example, the valve body of any of thedescribed excess flow valves can include a gauge port that allows an enduser to perform leak testing. As another example, any of the describedexcess flow valves can include a flow strainer mounted at the inlet portand/or the outlet port in order to reduce the amount of solidcontaminants in the process transfer or control system. Moreover, one ormore different members can be introduced around the driving element 158and the valve member 162 so that the opening action is accomplished witha “pressure balanced” member. In one example, the pressure balancedmember can take the form of a piston that is slidably disposed againstthe valve member 162 and is initially only exposed to inlet pressure,but which allows flow once it slides through the valve member 162 (seeFIG. 16). In another example, the pressure balanced member can take theform of a butterfly type element that allows flow once pivoted. In yetanother example, the pressure balanced member can take the form of aflat element that slides over the valve member 162. In any event, byutilizing one or more different pressure balanced members, thiseliminates the need for initial pressure equalization, as the openingvalve member will be at static equilibrium almost immediately after thepressure balanced member is opened.

Based on the foregoing description, it should be appreciated that thevalve described herein provides safe and effective excess flow closurefunctionality, but does so with minimal flow-restriction, therebyminimizing, if not eliminating, flow disruption and cavitation, which isa problem caused by known excess flow valves, especially when installedin a pump supply line. The valve described herein also has a break-awaysafety feature that facilitates break-off in the event of an accidentthat damages downstream piping, which serves to protect the integrity ofthe valve sealing area and sealingly contains fluid within and upstreamof the valve.

1. A shut-off valve for use in a fluid transport or storage system,comprising: a body defining an inlet port, an outlet port, and a fluidflow passageway extending between the inlet and the outlet; a seatarranged in the body adjacent the outlet port; a shaft at leastpartially disposed in the body; a driving element disposed in the bodyand coupled to the shaft; and a valve member disposed in the body andoperatively coupled to the shaft, the valve member movable between aclosed position, in which the valve member sealingly engages the seat toseal the outlet port, and an open position, in which the valve member isspaced away from the outlet port and substantially outside of the fluidflow passageway, such that the valve member provides minimalflow-restriction to fluid flowing through the fluid flow passageway. 2.The shut-off valve of claim 1, wherein the valve member automaticallymoves to the closed position responsive to fluid flow through the fluidflow passageway greater than a predetermined limit.
 3. The shut-offvalve of claim 2, wherein the valve member includes a bleed portconfigured to facilitate bleeding through the fluid flow passageway whenthe fluid flow through the fluid flow passageway is greater than thepredetermined limit.
 4. The shut-off valve of claim 1, wherein thedriving element is disposed between an exterior wall of the valve bodyand the valve member.
 5. The shut-off valve of claim 1, furthercomprising a first biasing element disposed between the driving elementand the valve body, the first biasing element configured to bias thedriving element to a closed position.
 6. The shut-off valve of claim 5,further comprising a second biasing element arranged to bias the drivingelement and the valve member toward one another.
 7. The shut-off valveof claim 1, wherein the shaft protrudes outward of the body and isadapted to be coupled to an external actuator for controlling the shaft.8. The shut-off valve of claim 7, wherein the shaft is movable about anaxis substantially perpendicular to the fluid flow passageway.
 9. Theshut-off valve of claim 8, wherein the shaft is rotatable about theaxis, and wherein the valve member comprises a swinging valve member.10. The shut-off valve of claim 8, wherein the shaft is slidable alongthe axis.
 11. The shut-off valve of claim 1, further comprising anadjuster for adjusting the excess flow capacity, the adjuster configuredto engage the drive member to change a position of the drive member inthe closed position.
 12. A shut-off valve for use in a fluid transportor storage system, comprising: a body defining an inlet port, an outletport, and a fluid flow passageway extending between the inlet port andthe outlet port; a seat arranged in the body adjacent the outlet port; ashaft at least partially disposed in the body; and a control assemblydisposed in the body and operatively coupled to the shaft, the controlassembly movable between a closed position, in which a portion of thecontrol assembly sealingly engages the seat to seal the outlet port, andan open position, in which the control assembly is spaced away from theoutlet port and substantially outside of the fluid flow passageway, suchthat the control assembly provides minimal flow-restriction to fluidflowing through the fluid flow passageway.
 13. The shut-off valve ofclaim 12, wherein the control assembly comprises a driving element and avalve member, the driving element configured to move the valve member,responsive to actuation of the shaft, between a closed position, inwhich the valve member sealingly engages the seat to seal the outletport, and an open position, in which the valve member is spaced awayfrom the outlet port.
 14. The shut-off valve of claim 12, wherein thevalve member automatically moves to the closed position responsive tofluid flow through the fluid flow passageway greater than an excess flowcapacity of the shut-off valve.
 15. The shut-off valve of claim 12,further comprising a first biasing element disposed between the drivingelement and the valve body, the first biasing element configured to biasthe driving element to a closed position.
 16. The shut-off valve ofclaim 15, further comprising a second biasing element arranged to biasthe driving element and the valve member toward one another.
 17. Theshut-off valve of claim 12, wherein the shaft is rotatable about an axissubstantially perpendicular to the fluid flow passageway.
 18. Theshut-off valve of claim 12, wherein the shaft is slidable along an axissubstantially perpendicular to the fluid flow passageway.
 19. Theshut-off valve of claim 18, further comprising a ramp arranged in thevalve body, the ramp defining a guide path oriented at an angle relativeto the axis, wherein the shaft is coupled to the control assembly via alinkage element guided by the ramp.
 20. A shut-off valve for use in afluid transport or storage system, comprising: a body defining an inletport, an outlet port, and a fluid flow passageway extending between theinlet and the outlet; a seat arranged in the body adjacent the outletport; a shaft at least partially disposed in the body; a driving elementdisposed in the body and coupled to the shaft; a valve member disposedin the body and operatively coupled to the shaft, the valve membermovable between a closed position, in which the valve member sealinglyengages the seat to seal the outlet port, and an open position, in whichthe valve member is spaced away from the outlet port and substantiallyoutside of the fluid flow passageway, such that the valve memberprovides minimal flow-restriction to fluid flowing through the fluidflow passageway; and a break-away safety mechanism comprising acircumferential channel formed in the valve body between the outlet portand the seat.